1. Field of the Invention
The present invention relates to an apparatus for treating as-spun or zero twist multifilament yarn with fluid which interlaces the yarn by the effect of a fluid, thus producing yarn with high coherence.
2. Description of Related Art
A yarn made of an as-spun multifilament is interlaced primarily because it has poor coherence which prevents easy handling.
In the apparatus for treating yarn with fluid designed to interlace the as-spun yarn by the effect of a fluid, the yarn to be interlaced is allowed to run between a pair of components and a fluid is ejected from one of the components, thereby periodically forming interlaced portions and opened portions, in which opened portions the filaments are separated in a spindle shape, on the yarn. Thus, the yarn will be Given the coherence, which is equivalent to that of twisted yarn, despite that the yarn has hardly any twist, or no twist.
In this case, for the interlacing to be provided on the yarn, the shorter the interlacing cycle, the higher the coherence of the yarn results.
As such a fluid-treating apparatus, those apparatuses, for example, which were disclosed in U.S. Pat. No. 3,262,179, Unexamined Japanese Patent Publication (KOKAI) No. 61-194243, U.S. Pat. No. 3,115,691, and Unexamined Japanese Patent Publication No. 59-66532, are known.
In the apparatus for interlacing multifilament yarn disclosed in the U.S. Pat. No. 3,262,179, one of two components, which provide yarn with coherence, has a spindle-shaped vortex cavity which measures in depth two to three times the gap G (mm) between the components and which has a set of fluid conduits having a crossing angle .theta. of 0 to 160 degrees for providing yarn with coherence and opening at the end thereof, the pitch of the fluid conduits at the opening being set at four to ten times the gap G (mm) between the components.
The fluid ejecting treating apparatus disclosed in Unexamined Japanese Patent Publication No. 61-194243 is a fluid ejecting treating apparatus which consists of a nozzle plate having a pair of fluid injection conduits and a collision plate which is provided as a counterpart thereof, the nozzle plate being provided with a concave section with a sector cross section which runs in the direction of the yarn between the pair of fluid injection conduits inclining so that they gradually move closer to each other and which has its center on the straight line perpendicular to the collision plate and has a curvature radius reaching a nozzle surface. In this fluid ejecting treating apparatus, embodiments, wherein a depth b (mm) of the concave section (round groove) having the sector cross section is set for 2.7, 3.7, and 4.7 times the diameter d (mm) of the fluid injection conduit, are disclosed.
The apparatus for interlacing multifilament yarn disclosed in the U.S. Pat. No. 3,115,691 allows yarn, which is to be interlaced, to run between a pair of components consisting of the first and second components, and a fluid is ejected from fluid conduits provided in one component toward the other component, thereby periodically forming interlaced portions and opened portions, in which opened portions the filaments are separated in a spindle shape, on the yarn.
The yarn interlacing apparatus disclosed in Unexamined Japanese Patent Publication No. 59-66532 has coherent components (9, 9') which have narrow grooves (10, 10'), through which yarn passes, provided on both ends of a collision plate (7) to prevent a fluid jet (6) from being discharged (see FIG. 5 of above document) and it is designed to forcibly interlace a false-binding point C of the yarn at the coherent components (9, 9') without being influenced by excessive or insufficient coherent force of the yarn, variations in tension applied to the yarn or dislocation of yarn (see FIG. 6 of above document).
In the apparatus for treating yarn with fluid disclosed under the U.S. Pat. No. 3,262,179 or Unexamined Japanese Patent Publication No. 61-194243, it was difficult to constantly form interlaced portions and opened portions in a regular interlacing cycle independently of the type or size of yarn by selecting an optimum shape for the two components which provide yarn with coherence. Missing interlaced portions occurred occasionally. Hence, these apparatus were not entirely satisfactory in manufacturing yarn with high interlacing property.
On the other hand, the apparatus disclosed in the U.S. Pat. No. 3,115,691 or Unexamined Japanese Patent Publication No. 59-66532 provides yarn with the same level of coherence as that of twisted yarn even though despite that the yarn has hardly any twist, or no twist; however, the fluid ejected from the fluid conduits is naturally discharged along the thread path of the yarn and no consideration is given to the discharge route in the case of the U.S. Pat. No. 3,115,691.
Hence, in the aforementioned apparatus, the discharged fluid flows along the thread path, resulting in problems. In a typical problem, the yarn, which runs between the first and second components and which is interlaced, is brought in contact with the first and second components at the incoming or outgoing point of the yarn and rubbed against them, thus causing problems such as frays or looseness of structure.
Likewise, in the case of the apparatus disclosed in Unexamined Japanese Patent Publication No. 59-66532, the coherent components (9, 9'), which are provided to prevent the discharge of the fluid jet (6), shut off the fluid discharged, disturbing the thread path of the yarn. As a result, the yarn frequently contacts the narrow grooves (10, 10') and the yarn is rubbed against them, causing problems such as frays and looseness of structure.